Blood vessel closure clip and delivery device

ABSTRACT

A clip for closing a puncture hole in a blood vessel comprises a ring  12  having a resiliently expandable circumference and a plurality of barbed prongs  14  extending at least approximately in the same direction from one edge of the ring. A device for deploying such a clip is also described.

This application is a 371 of PCT/IE03/00088, filed on Jun. 4, 2003.

FIELD OF THE INVENTION

This invention relates to a clip for closing a puncture hole in a bloodvessel, and to a device for closing a puncture hole using such a clip.

BACKGROUND

Numerous medical diagnostic and interventional procedures involve theuse of long catheters which are placed within the human vascular system.These catheters are delivered over guide wires to positions in the heartfor cardiac procedures and into the brain for neurological procedures.The point of entry is normally a puncture hole in the femoral artery inthe patient's groin. Once the procedure has been completed the catheterand guide wire are removed and the puncture hole must be closed in orderto prevent excessive bleeding and the possibility of infection.Traditionally this puncture hole has been closed by maintaining manualpressure at the puncture site until homeostasis occurs around thepuncture hole or placing sand bags on an area of the groin close to thepuncture hole and keeping the patient immobilised until homeostasisoccurs.

In recent times a number of medical devices have been developed andmarketed for the purpose of closing this puncture hole. These devicesfall broadly into two categories (a) mechanical closure devices such asthose which use sutures or staples to mechanically close the puncturehole, and (b) occlusion devices such as collagen plugs and gels.Examples of prior art in this area include U.S. Pat. Nos. 5,860,991 and6,322,580.

U.S. Pat. No. 5,860,991 describes a device for closing puncture holesutilizing a suture. The device is positioned into the artery over theguide wire until a blood signal appears at the proximal end indicatingproper position has been attained. At this point an internal anchor isdeployed and needles are advanced from outside the artery, through thearterial wall and into the anchor component to grab opposite ends of asuture loop. The needles are then retracted back into the device and thedevice is removed from the artery leaving the open ends of the sutureexternal on the patients skin. A knot is tied and run down the suturetightening the loop around the puncture hole and closing it. A cutterdevice is then used to cut the suture.

The problems associated with this device are the significant number ofsteps in its use, tying of the suture loop involves a sawing actionaround the puncture hole which could unintentionally cause the suture tocut its way through the hole, pushing needles from outside the artery toinside creates two additional puncture holes and finally a loop ofsuture remains inside the artery and has the potential to dislodgeplaque within the artery.

Another example of a mechanical closure device is described in U.S. Pat.No. 6,322,580 which uses a metallic staple to close the puncture hole.This device involves the use of a special dilator and sheath which areguided into the femoral artery over a guide wire. Once the guide wire isremoved internal stabilizers are activated and retracted against theinternal wall of the artery. The sheath dilator is then removed and astapler device is advanced through the sheath and the staple deployedinto the arterial wall. The stapler is then removed, the stabilisersdeactivated and the introducer sheath removed from the tissue tract.

Problems associated with this device include the use of a specialisedsheath which must be inserted over the guide wire and advanced into thetissue tract before the closure procedure can take place. In additiondelicate stabiliser type devices must be deployed within the arterybefore the stapler can be delivered to close the puncture hole. Once thestaple is delivered the staple device is removed from the sheath, theinternal stabilisers are then collapsed and retracted through thepuncture hole and into the sheath before the sheath itself can beremoved from the tissue tract.

While both devices described above are effective in terms of closingpuncture holes they are mechanically complex in nature in terms ofoperation. In addition a significant number of steps are involved in theprocedure. The end users of such devices are more familiar withcatheter-based technologies delivered over guide wires, combined withthe inflation and deflation of balloons. Therefore there is a need foran improved puncture closure device which operates in a manner moreconsistent with catheter based devices such as angiography andangioplasty catheters. In addition there is a need to reduce thecomplexity of such devices by reducing the number of components involvedand the number of steps involved in the procedure.

SUMMARY OF THE INVENTION

Accordingly, the present invention provides a clip for closing apuncture hole in a blood vessel, the clip comprising a ring having aresiliently expandable circumference and a plurality of barbed prongsextending at least approximately in the same direction from one edge ofthe ring.

The ring may be circular or any suitable closed-loop shape.

The invention further provides a device for closing a puncture hole in ablood vessel using a clip of the kind aforesaid, the apparatuscomprising an elongated body having a front end for insertion throughthe hole into the blood vessel and a clip expander positioned on thebody rearwardly of the front end for receiving the clip with its ringsurrounding the expander and its prongs projecting towards the front endof the body, the clip expander being actuable to resiliently expand thecircumference of the ring, the clip being movable forwardly in itsexpanded state so that the prongs pierce the tissue around the hole, andthe clip expander thereafter being actuable to release the clip so thatthe body and clip expander can be withdrawn from the ring.

In one embodiment the clip, herein referred to as a “ring occluder”, isplaced over a deflated balloon which in turn is bonded to the shaft of aplastics catheter. Inflation of the balloon exerts an outward expandingforce under the ring occluder causing it to expand to a diameterequivalent to a fully expanded diameter of the balloon on which it sits.Barbed legs extend from one edge of the occluder ring for a distance of3-5 mm. The catheter has three lumen, one provides a channel for liquidto inflate the balloon, one is a channel for blood and the third channelaccommodates the guide wire.

In clinical use the catheter is positioned on the guide wire anddelivered over the guide wire through the tissue tract and into theblood vessel. The catheter is advanced until a blood signal appears atthe blood back port. This indicates that the blood entry port is nowpositioned within the blood vessel. The catheter is now retracted untilblood flow stops indicating that the blood entry port is now positionedwithin the puncture hole and the ring occluder is positioned apre-determined distance form the wall of the blood vessel. The guidewire may now be removed. The balloon is then inflated using salinesolution which in turn causes the ring occluder to increase in diameterand expand outward into the tissue tract. The diameter of the balloon onthe rear side of the ring occluder is greater in diameter so as toprovide a shoulder or edge to advance the ring occluder forward. Oncefully expanded the catheter is pushed forward causing the barbed legs ofthe ring occluder to penetrate the surrounding tissue and arterial wallin the proximity of the puncture hole. The catheter continues to advanceuntil significant forward resistance is met. This indicates to the userthat the catheter should not be advanced any further as the barbed legsshould now be positioned within the arterial wall. The expanding balloonis then deflated, the guide wire removed from the catheter and thecatheter removed from the tissue tract. On removal of the catheter therecoiling force of the ring occluder will pull the edges of the puncturehole together thereby sealing the hole closed.

In another embodiment the balloon is replaced by a sliding collar whichhas splines which are forced mutually outwards to deform the ringoccluder.

The advantage of such devices are that they are significantly simpler tooperate than previously described mechanical closure devices. Inaddition, the mode of operation of the balloon device is consistent withthat of other devices used by interventional radiologists andcardiologists in that it provides a catheter delivered over a guide wirewith a balloon which is inflated from an external port.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments on the invention will now be described, by way of example,with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of one embodiment of a ring occluderaccording to the invention in both its unexpanded and expandedconditions.

FIG. 2 is a perspective view of a second embodiment of a ring occluderin its unexpanded and expanded conditions.

FIG. 3 is a plan view of a first embodiment of catheter delivery devicefor the ring occluder of FIG. 1 or FIG. 2.

FIG. 4 is an enlarged view of the delivery device of FIG. 3 in theregion of the ring occluder and inflatable balloon.

FIG. 5 is a cross sectional view of the catheter on the plane A-A ofFIG. 3.

FIGS. 6-10 illustrate successive stages of the catheter delivery devicein use.

FIG. 11 is a perspective view of a second embodiment of catheterdelivery device in a non-expanded condition.

FIG. 11(A) is a cross sectional view of the second embodiment ofcatheter on the plane A-A of FIG. 12.

FIG. 12 is an elevational view of the device shown in FIG. 11.

FIG. 13(A) is an elevational view of the ring occluder deployment means(expander) of the second embodiment of catheter delivery device in itsinitial rest position.

FIG. 13(B) is an elevational view of the expander of FIG. 13(A) in itsmid-forward and fully expanded state.

FIG. 13(C) is an elevational view of the expander of FIG. 13(A) in itsfully forward and collapsed state.

FIGS. 14 and 15 illustrate successive stages of the second embodiment ofcatheter delivery device in use.

DETAILED DESCRIPTION OF THE INVENTION

Referring first to FIG. 1, a ring occluder 10 for closing a puncturehole in a blood vessel comprises a circumferentially continuous metalring 12. The circumference of the ring 12 is sinuous and the ring has aplurality of sharp metal prongs 14 extending at least approximately inthe same direction from one edge (in FIG. 1 the lower edge) of the ring12. The prongs are 3-5 mm in length and extend from alternate minima ofthe sinuous shape. The prongs 14 are barbed, meaning in the presentcontext that they are configured to resist withdrawal once theypenetrate tissue. The prongs 14 preferably mutually converge slightlytowards the centre axis of the ring 12. FIG. 1( a) shows the ringoccluder in its non-expanded state, while FIG. 1( b) shows the ringoccluder in its expanded state where the pitch between the peaks of thesinuous configuration have been increased in a manner which providesuniform expansion of the ring at all points on its circumference. Thepitch between the barbed prongs increases accordingly.

FIG. 2( a) shows an alternative embodiment of ring occluder 10′ in itsnon-expanded state. In this case the circumference of the ring 12′ ismade up of a plurality of oval-shaped segments 16 each with alongitudinal central slit 18. The oval segments 16 are disposedside-by-side round the ring 12 with their longitudinal axessubstantially parallel. Each oval segment 16 is joined to the next by anarrow central waist 20. On expansion of the ring as illustrated in FIG.2( b) the oval segments expand to a more round or open configurationtherefore increasing the overall diameter of the ring 12 and the pitchbetween the barbed legs 14 which extend from the base of every secondoval segment.

In both cases the material used to fabricate the ring occluders 10 and10′ is such that permanent metal deformation does not occur on expansionof the occluder from its non-expanded state to its expanded state. Theforce exerted on the occluders is such that they remain within theelastic range of the material used thereby ensuring that when theexpanding force is removed the occluder returns resiliently to itsnon-expanded state. Preferably the diameter of the ring 12 can beresiliently increased by a factor of three with return substantially toits original diameter upon removal of the expanding force. An example ofa suitable material for making the occluder is Nitinol or Memory Metal.

FIGS. 3 to 5 show a first embodiment of catheter delivery device with aring occluder 10 in position (the device could just as well be used withthe ring occluder 10′). The catheter 22 is a flexible, elongatedplastics body having a longitudinal bore 24 (FIG. 5) by which thecatheter can be slid along a pre-positioned guide wire 26. The front end28 of the catheter 22 is tapered down onto the guide wire 26 whichguides it into position within the blood vessel 30, FIG. 6, through ahole 32 in the sidewall of the blood vessel. Between the front end 28and the ring occluder 10 is a blood entry port 34. The port 34 allowsblood to enter a further longitudinal bore 38 in the catheter 22. Aninflatable enclosure (“balloon”) 40 is positioned on the catheter 22approximately 5 cm to the rear of the extreme forward tip 28′ of thefront end 28. The balloon 40 coaxially surrounds the catheter and in itsdeflated state lies tightly against the catheter body. The ring occluder10 is positioned on the balloon 40 toward its forward end, the ring 12coaxially surrounding the balloon and catheter. A hub 42 is positionedat the rear end of the catheter 22 from which extends a blood port 44connected to bore 38 within the catheter, which in turn is connected toblood entry port 34. In addition, there is a balloon inflation port 46connected to a further longitudinal bore 48 in the catheter 22, the bore48 communicating with the interior of the balloon 40. The port 46 allowsfluid under pressure (such as a saline solution) to be delivered intothe balloon 40 to inflate it, and also allows fluid in the balloon to bevented to allow it to revert to its deflated state.

FIG. 4 is a view of the device in the region of the ring occluder 10.The balloon 40 is formed with two axially adjacent regions 40 a, 40 bsuch that when the balloon is inflated these regions have differentdiameters, FIG. 7. In particular, when the balloon is inflated the frontregion 40 a, around which the occluder 10 is positioned, has a lesserdiameter than the adjacent rear region 40 b. The reason for this is toprovide a shoulder 40 c behind the ring 12 with which the ring occluder10 can be pushed forward into the tissue surrounding the puncture hole32 by pushing the catheter 22 as a whole in a forward direction. Onlythe ring 22 is positioned on the balloon 40. The barbed prongs 14 extendfreely in a forward direction and converge slightly towards the catheterbody. In order to ensure that, when the balloon is inflated, the region40 b does not expand at the expense of the region 40 a, the region 40 band shoulder 40 c are made of a thicker material than the region 40 a.

FIGS. 6 to 10 illustrate the device in clinical use. Referring first toFIG. 6, the catheter 22 is positioned on the guide wire 26 and slidforwardly thereon through the tissue tract until the front end 28 of thecatheter enters the blood vessel 30. The catheter 22 is advanced forwarduntil the blood entry port 34 enters the blood vessel indicated by bloodflowing from the blood back port 44. Advancement of the catheter isstopped and the balloon 40 is then inflated, as illustrated in FIG. 7,by fluid pressure applied at the port 46. Inflation of the ballooncauses the ring occluder 10 to resiliently expand. Once fully expandedthe catheter 22 is advanced forwardly as shown in FIG. 8. In doing sothe shoulder 40 c on the balloon 40 pushes against the ring occluder 10causing the prongs 14 to penetrating overlying tissue and the arterialwall. The catheter 22 is advanced until significant resistance preventsany further advancement. This indicates proper position of the ringoccluder 10. Now the balloon 40 is fully deflated by venting through theport 46 resulting in some resilient contraction of the ring occluder 10around the catheter 22 as illustrated in FIG. 9. Once fully deflated theguide wire 26 and catheter 22 are removed from the tissue tract and thepuncture hole 32 causing the ring occluder 10 to resiliently contract toits initial state thereby pulling the edges of the puncture hole 32together and effecting homeostasis. The closed ring occluder 10 remainspositioned around the puncture hole on the artery as illustrated in FIG.10.

Although the foregoing has shown the ring 12 or 12′ as circular, and theballoon 40 circularly symmetric around the catheter 22, the ring doesnot need to be circular but can be any closed-loop shape as dictated bythe cross-section of the balloon which can also vary. The term “ring” isto be interpreted accordingly.

FIGS. 11 to 13 show an alternative embodiment of a catheter deliverydevice for the ring occluder 10 or 10′. In place of the balloon 40 usedin the previous embodiment, a mechanical expander is used; otherwise,all features of the previous embodiment may be present in the currentembodiment. The mechanical expander comprises an oversleeve 50 on thecatheter 22. FIG. 11(A) shows a cross-section through the catheter inthe region of the oversleeve 50. The catheter has a longitudinal guidewire bore 24 and blood return bore 38 as previously described, and thesleeve 50 is seen coaxially surrounding the catheter body. The forwardend 52 of the sleeve is fixed to the outer surface of the catheter,while the rear end 53 of the sleeve 50 is slidable on the catheter 22. Asection of the sleeve 50 intermediate its ends, onto which the occluderis mounted in use, is slit longitudinally to form a series of spines 54.Each spline 54 has four hinge points 54 a, 54 b, 54 c and 54 d, thehinge points 54 a and 54 d being at the front and rear ends of thespline and the hinge points 54 b and 54 c being intermediate them. Thetwo intermediate hinge points 54 b, 54 c generally align with the upperand lower edges respectively of the expandable ring 12 section of theoccluder 10 as illustrated in FIG. 12.

In the unexpanded state as shown in FIG. 13( a) the splines 54 lie flushwith the catheter. If the rear end 53 of the sleeve 50 is slid along thecatheter 22 towards the fixed front end 52 the splines 54 are forcedmutually radially outwardly as shown in FIG. 13( b) thus resilientlyexpanding the occluder 10 and at the same time advancing it in a forwarddirection. With continued advancement of the rear end 53 of the sleevethe splines collapse mutually inwardly down onto the catheter thusreleasing the occluder 10 from the splined section.

In clinical use the catheter 22 is slid over a guide wire 26 as shown inFIG. 14 until a blood signal is received at the port 44 thus indicatingproper positioning. At this point the rear end 53 of the sleeve 50 isadvanced causing the occluder 10 to resiliently expand andsimultaneously advance to stab the wall 30 of the artery, FIG. 15( a).As the rear end 53 of the sleeve is advanced further it releases theoccluder 10, FIG. 15( b), so that the catheter and guide wire can beretracted from the puncture hole 32 allowing the occluder 10 to fullycontract and close the puncture hole, FIG. 15( c).

The invention is not limited to the embodiments described herein whichmay be modified or varied without departing from the scope of theinvention.

1. A device for closing a puncture hole in a blood vessel, comprising:an elongated body having a front end for insertion through the hole intothe blood vessel; a clip expander positioned on the body rearwardly ofthe front end, the clip expander comprises a sleeve surrounding the bodywhich has one end fixed relative to the body, a section of the sleeveintermediate its ends being slit longitudinally to form a plurality ofsplines which can be forced mutually outwardly by sliding the other endof the sleeve along the body towards the fixed end of the sleeve; a cliphaving a ring disposed around the expander and prongs projecting towardsthe front end of the body, the clip being mounted on the splined sectionof the sleeve; and wherein the clip expander is actuable to resilientlyexpand the circumference of the ring, the clip being movable forwardlyin its expanded state so that the prongs pierce the tissue around thehole, and the clip expander thereafter being actuable to release theclip so that the body and clip expander can be withdrawn from the ring.2. The device of claim 1, wherein the prongs converge slightly towardsthe center of the ring.
 3. The device of claim 1, wherein the ring issinuous.
 4. The device of claim 1, wherein the ring comprises aplurality of elongated segments each with a longitudinal center slit,the segments being disposed side by side around the ring with theirlongitudinal axes substantially parallel and being joined each to thenext by a relatively narrow waist.
 5. The device of claim 1, wherein thebody has a longitudinal bore to slidably accommodate a guide wirepre-positioned at the puncture hole.
 6. The device of claim 1, whereinthe body has a longitudinal bore to serve as a blood return channel. 7.The device of claim 1, wherein the splines are hinged such that as thesplines move mutually outwardly to expand the ring they also advance theclip towards the forward end of the body.
 8. The device of claim 7,wherein after advancing the clip, further movement of the said other endof the sleeve towards the fixed end moves the splines mutually inwardlyto release the clip.